Single workpiece processing chamber

ABSTRACT

A process chamber for processing semi-conductor wafers. The chamber includes at least one rotor within the process chamber. The rotor is adapted to receive and/or process semi-conductor wafers. The top of the process chamber also includes a tiltable rim. This rim tilts from a non-inclined position to an inclined position. The wafers may be loaded into and unloaded from the process chamber when the rim is in its inclined position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a Division of U.S. patent application Ser. No.11/075,099 filed Mar. 8, 2005, now U.S. Pat. No. 8,118,044, and whichclaims priority to U.S. Patent Application No. 60/552,642, filed Mar. 4,2004, both incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates to surface preparation, cleaning, rinsing anddrying of workpieces, such as semiconductor wafers, flat panel displays,rigid disk or optical media, thin film heads or other workpieces formedfrom a substrate on which microelectronic circuits, data storageelements or layers, or micro-mechanical elements may be formed. Theseand other similar articles are collectively referred to as a “wafer” or“workpiece.” Specifically, this invention relates to a workpiece processchamber for treating a semiconductor wafer, and more particularly to anovel process chamber for loading and processing a semiconductor wafer.The invention also relates to a new method for treating a semiconductorwafer.

SUMMARY OF THE INVENTION

This invention is a system for processing a semi-conductor wafer. Thesystem may include a number of process chambers. At least one of theseprocess chambers is a novel process chamber. The invention is also amethod for treating a semiconductor wafer with that novel processchamber.

The use of a tiltable rim in connection with a process chambersimplifies the construction of the process chamber, and should thus leadto a more reliable, lower-maintenance process chamber. The use of thetiltable rim also permits a variety of processing steps to be donewithin a single process chamber. Particularly, the Use of the tiltablerim permits the insertion of a wafer with the first side, i.e., the sidethat is intended to be processed, facing up. The tiltable rim alsopermits three processing operations to be performed in a single processchamber. For example, up to two or more processing steps may beperformed in an upper compartment of the process chamber, and one ormore processing steps may be performed in a lower compartment of theprocess chamber. The use of a tiltable rim, especially in conjunctionwith its built-in channels, also helps to keep the semi-conductorwafers, and the robot end effector that inserts and removes thosewafers, clean during wafer processing. This will in turn reduce thelikelihood of damaging the resulting microelectronic devices.

The use of a pivoting arm or swing arm in conjunction with the tiltablerim has additional beneficial effects. Typically, the pivoting arm movesfrom a second position to a first position in a sweeping motion, acrossthe face of the spinning wafer, so that fluid being discharged from thepivoting arm impinges upon and contacts virtually the entire surface ofthe wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a system for processing a single workpiece,such as a semi-conductor wafer, in accordance with an embodiment of theinvention.

FIG. 1A is a perspective view of a portion of the processing system ofFIG. 1.

FIG. 1B is an isometric view illustrating a portion of the processingsystem of FIGS. 1 and 1A in accordance with an embodiment of theinvention.

FIG. 2 is a perspective view of the novel process chamber, with thetilting rim in its inclined position, to facilitate either the loadingor the unloading of a semi-conductor wafer from the process chamber.

FIG. 3 is a partial sectional view of the process chamber of FIG. 2.

FIG. 4 is a view of the process chamber of FIG. 3, but with the tiltingrim in its non-inclined position.

FIG. 5 is a perspective view of the process chamber of FIG. 2, but withboth the wafer and the rotor in the lower compartment of the processchamber, and inverted from their orientations as shown in FIG. 2, sothat the first side of the wafer faces downwardly.

FIG. 6 is a partial sectional view of the process chamber shown in FIG.5.

FIG. 7 is a perspective view of the process chamber of FIGS. 2 and 5,but with the rotor and wafer returned to their original positions, andshowing a pivoting arm in its first position above the wafer, fordelivering processing fluids to the wafer.

FIG. 8 is a partial sectional view of the process chamber of FIG. 2, buttaken along different section lines than those resulting in FIG. 3, andshowing the tiltable rim in its inclined position.

FIG. 9 is a partial sectional view of the process chamber of FIG. 8, butwith the tiltable rim in the non-inclined position.

FIG. 10 is an enlarged, perspective view of the underside of thetiltable rim.

DETAILED DESCRIPTION

The invention is a system for processing a semi-conductor wafer, a novelprocess chamber that is a part of that system, and a novel method ofprocessing a semi-conductor wafer, preferably using that novel processchamber.

FIG. 1 shows a top plan view of the system 10 of the invention. Thesystem 10 shown in FIG. 1 includes ten process chambers, each of whichis represented in FIG. 1 by a circle. It will be understood that thesystem 10 may include a greater or lesser number of process chambers.The process chambers may be configured to process microelectronicworkpieces, such as 200 or 300 mm diameter semiconductor wafers. Theprocess chamber of the present invention is designed to be utilized in aconventional existing processing system 10, for example, as disclosed inpending U.S. Pat. Nos. 6,900,132 and 6,930,046, both incorporated hereinby reference. This-system 10 may include different process stations orchambers, such as but not limited to those that perform electrolessplating and electroplating. More particularly, these chambers serve as ameans for plating and otherwise processing microelectronic workpieces.These systems may also be modularized, and thus may be readily expanded.

FIG. 1A shows the enclosure 11 in which the process chambers of theinvention are enclosed. The top of this enclosure 11 includes a HEPAfilter 13. Air is drawn into the enclosure 11 through this HEPA filter13. After entering the enclosure 11 through this HEPA filter 13, the airpasses through the process chambers 12 of the invention, and is thendrawn out through exhaust ducts connected to the bottom of the enclosure11.

FIG. 1B is an isometric view illustrating a portion of the processingsystem of FIGS. 1 and 1A. As will be explained below, the inventionincludes a tiltable rim 24 and a shroud 40. The tiltable rim 24 and theshroud 40 are secured to the deck 19 (see FIG. 1B) of the processingsystem. Particularly, as may be seen in FIG. 3, the base portion 21 ofthe shroud 40 is secured to the deck 19.

The novel process chamber 12 is shown in perspective in FIG. 2. As notedabove, the shroud and the tiltable rim of the novel process chamber 12of the invention, which may be seen in FIG. 2, may be placed directlyabove the pre-existing chamber 15 of FIG. 1B, i.e., on the deck 19. Thisprocess chamber 12 may be but one of the many different chambers,performing many different functions, typically included in system 10.

As shown in FIGS. 2 and 3, the novel process chamber 12 of the inventionis designed to perform processing steps on a single workpiece, such as asemiconductor wafer 14. The semi-conductor wafer 14 is fed to theprocess chamber 12 by a robot arm 16 and a robot end effector 18. Therobot arm 16 and the robot end effector 18, and their use in connectionwith the processing of semi-conductor wafers, are both well-known in theart.

The robot arm 16 and robot end effector 18 both place an unfinishedwafer 14 onto, and remove a finished wafer 14 from, a rotor 20. In thispreferred embodiment, the process chamber 12 includes a single rotor 20.Two or more rotors, however, may also be used.

The rotor 20 is a part of a rotor assembly 22. The rotor assembly 22receives and carries the wafer 14, positions the wafer 14 forprocessing, and is capable of rotating or spinning the wafer 14 duringprocessing or drying steps.

In order to permit loading and unloading of the wafer 14, the processchamber includes a tiltable rim 24. This tiltable rim 24 is movablebetween a non-inclined position (FIG. 4-7) and an inclined position(FIGS. 2 and 3). When the tiltable rim 24 is in its non-inclinedposition, as shown in FIGS. 4-7, that rim 24 closes an opening thatotherwise permits wafers 14 to be loaded into and unloaded from theprocess chamber 12. Conversely, when the tiltable rim 24 is in itsinclined position, as shown in FIGS. 2 and 3, the rim 24 opens a portionof the process chamber 12. When the rim 24 is in this inclined position,the wafers 14 may be loaded into and unloaded from the process chamber12.

As shown in FIGS. 2 and 3, the tilting of the rim 24 permits access tothe rotor 20 by the robot arm 16 and the robot arm effector 18. Thetilting of the rim 24 thus permit wafers 14 to be loaded into theprocess chamber 12, and onto the rotor 20, and subsequently unloaded.Small hook-like fingers 30 arising from the rotor 20 are used to securethe wafer 14 to the rotor 20 during processing of the wafer 14.

The tiltable rim 24 pivots about two pivot points or hinges. One ofthese hinges 26 is shown in FIG. 2. The other hinge is not shown in FIG.2. It is secured to the process chamber 12 at a portion of the chamberthat is obscured in FIG. 2, on the opposite side of the rim 24. As maybe seen by a comparison of FIGS. 2 and 7, the tiltable rim 24 is movedbetween its inclined and non-inclined position by the actuation of apneumatic lift arm mechanism 28. Particularly, this pneumatic lift armmechanism 28 is a double acting pneumatic cylinder with a pivotingclevis mount. Magnetic sensors, available from the vendors of suchpneumatic cylinders, are used to indicate the two positions, i.e., theraised and lowered positions, of the cylinder. Both of the positions ofthe cylinder are defined by mechanical hard stops.

From the above, it will be appreciated that the tiltable rim 24 and itsactuating mechanisms are simple in construction, which should result ina more reliable, lower maintenance operation.

The process chamber 12 may also include a pivoting arm or swing arm 32,as may best be seen in FIGS. 2 and 7. The pivoting arm 32 preferablymoves in a sweeping motion between two end positions. Its movement iseffected by a 50 watt motor and harmonic gear reducer combination. Theharmonic gear reduction is 50:1. As with the pneumatic lift armmechanism 28, the ends of travel of this pivoting or swing arm 32 aredefined by hard stops. A home (zero) position is established byregistering the pivoting arm 32 against one of the two hard stops. Anincremental and absolute encoder on the motor is used to define anyother positions, relative to the home position of the pivoting arm 32.

The pivoting arm 32 facilitates the delivery of processing fluids to thewafer 14. In this embodiment, the pivoting arm 32 is movable from afirst position to a second position. The first position of the pivotingarm 32 is shown in FIG. 7. In this first position, the pivoting arm isdisposed above the wafer 14 for the delivery of those processing fluidsto the wafer 14.

As shown in FIG. 7, the pivoting arm 32 includes two tubes 34 and 36.Any gas or liquid can be dispensed through these tubes 34 and 36,depending on the processing needs of the manufacturer.

In one preferred embodiment, tube 36 facilitates the delivery ofdeionized water to the wafer 14. In contrast, tube 34 facilitates and isdedicated to the delivery to the wafer 14 of either nitrogen alone, or acombination of nitrogen and isopropyl alcohol. Conventional valves (notshown) are used to control the delivery of these gases and liquids tothe respective tubes 34 and 36.

The second position of the pivoting arm 32 is shown in FIG. 2. In thissecond position, the pivoting arm 32 is disposed to the side of thewafer 14, and above the tiltable rim 24. In this second position, theend of the pivoting arm overlies a drip catch tray 38. The drip catchtray 38 collects liquids that drip from either of the two nozzle tips atthe ends of the pivoting arm 32. The drip catch tray 38 also collectsand facilitates the removal of deionized water, between the conventionalvalves and the nozzle tips, which occasionally must be purged from tube32. The drip catch tray 38 is connected to means for transporting thesewaste liquids to a remote location for disposal. Here, the drip catchtray 38 feeds into channels 44.

The use of a pivoting arm 32 or swing arm in conjunction with thetiltable rim 24 has many beneficial effects. Typically, the pivoting armmoves from a second position to a first position in a sweeping motion,across the face of the spinning wafer 14, so that fluid being dischargedfrom the pivoting arm 32 impinges upon and contacts virtually the entiresurface of the wafer 14. The pivoting arm 32 thus permits directimpingement of deionized water onto virtually the entire surface of thespinning wafer 14. Of course, the pivoting arm 32 can also be used tocause impingement of nitrogen, isopropyl alcohol, and any other liquidor gas, onto the entire surface of the wafer 14.

The process chamber 12 can also include an upwardly-disposed shroud 40.As noted above, the shroud 40 is positioned below the tiltable rim 24,but above the deck 19, as shown in FIGS. 1B and 3. The shroud 24 mayfacilitate higher and more efficient air flow across the perimeter andsurface of the first side 42 of the wafer 14. This higher and moreefficient air flow may keep particles from remaining on the surface ofthe wafer 14. In addition, the shroud 40 may assist in keeping withinthe process chamber 12 the vapors of chemicals used to process the wafer14. Drying air enters the unit shown in FIGS. 1, 1A and 1B through theHEPA filters 13. It then passes over the wafer 14, and into the top ofthe shroud 40. Air is discharged from the bottom of the shroud 40, andthen continues downward through a portion of the radiused vent openings17 shown in FIGS. 1 and 1B. The remaining portions of the four radiusedvent openings 17 are covered by a flange at the base 21 of the shroud40.

As shown in FIG. 5, at least one channel 44 is positioned within thetiltable rim 24. A preferred embodiment may include three channels, andtwo of these three channels 44 are shown in FIG. 5. As a wafer 14 isspun during processing to remove rinse water and dust or dirt from itssurface or first side 42, the water and entrained particulates aremoved, by centrifugal force, outwardly and towards the rim 24. As thewater approaches the rim 24, it enters the channels 44 within the rim24. Those channels 44 collect and transport the fluid away from thefirst side 42 of the wafer, and ultimately out of the process chamber12. In this way, the channels 44 and tiltable rim 24 combine to reducethe likelihood that this fluid will reach the bottom of the processchamber 12.

Much of the fluid collected within the channel 44 is removed from theprocess chamber 12 through a flexible drain hose fitting 46. Thisflexible drain hose fitting 46 may best be seen in FIG. 3. Some of thefluid connected within the channel 44 is removed through this hosefitting 46 during the rinsing and spin drying of the wafer 14 by meansof the rotor assembly 22. The remainder of the fluid in the channels 44is discharged during the removal of the treated wafer 14 by the robotend effector 18. Particularly, as the tiltable rim 24 is moved from itsnon-inclined position to the inclined position, as shown in FIG. 3, anyremaining fluid within the channels 44 moves towards the lowest point ofthe rim 24, i.e., towards the flexible drain hose fitting 46. All fluidthat drains out of the flexible drain hose fitting 46 is then dischargedto a remote location for disposal.

As discussed above, air is drawn through process chambers, such asprocess chamber 12, for drying the wafers 14. This drying air enters theprocess chamber 12 as a result of the generation of vacuum conditionscreated near the bottom of the process chamber 12. As a result of thesevacuum conditions, air is drawn from the ambient above the top of theprocess chamber 12, over the wafer 14, and down through the bottom ofthe chamber 12.

Exhaust ports 48 are provided in the tiltable rim 24. Specifically,these exhaust ports 48 are formed within or placed within the tiltablerim 24. One of these exhaust ports 48 is shown in FIGS. 3, 8, and 9,while both exhaust ports 48 are shown in FIG. 10. Each of the exhaustports 48 include upper ends 50.

FIG. 8 shows the tiltable rim 24 in its inclined position. Nevertheless,as may be appreciated by a review of this FIG. 8, when the tiltable rim24 is in its non-inclined position, and the rotor assembly 20 and wafer14 are in the upper compartment of the process chamber 12, as shown inthis FIG. 8, the upper ends 50 of these exhaust ports 48 are below thehorizontal plane of the wafer 14.

The process chamber also includes a pair of exhaust ducts 52. Each ofthe exhaust ducts 52 is associated with a single exhaust port 48. One ofthe exhaust ducts 52, and its associated exhaust port 48, is depicted inFIGS. 8 and 9.

When the tiltable rim 24 is in its inclined position, as shown in FIG.8, the exhaust port 48 is separated from the exhaust duct 52. Incontrast, when the tiltable rim 24 is in its non-inclined position, asshown in FIG. 9, the exhaust port 48 sealingly engages the exhaust duct52. A portion of the drying air that passes over the wafers 14 may enterthe exhaust ports 48, and then enter the exhaust ducts 52 for dischargefrom the process chamber 12.

During the processing cycle, a relatively small portion of the liquidthat is discharged from the pivoting arm 32 for rinsing the wafer 14 maybe diverted towards the exhaust ports 48 and exhaust ducts 52. Thisliquid is entrained in air to form what is essentially an atomizedvapor. This atomized vapor leaves the tiltable rim 24 through theexhaust ports 48 and the exhaust ducts 52. The atomized vapor is thencarried out of the process chamber 12.

By removing both drying air and liquids from the area near the wafer 14as it is being processed, the shroud 40, exhaust ports 48, and exhaustducts 52 together combine to more effectively direct drying air over thewafers 14. In this way, the shroud 40, exhaust ports 48, and exhaustducts 52 combine to reduce the likelihood that tiny particles of dust,dirt, metals, and manufacturing chemicals will remain upon the surfaceof the wafers 14 during their processing. This in turn reduces thelikelihood that the resulting microelectronic devices will be damaged.

The lift/rotate actuator 54 can move the wafer 14 from an uppercompartment of the process chamber 12, as shown in FIG. 4; to a lowercompartment of the process chamber, as shown in FIG 6.

As it moves the wafer 14 from the upper to the lower compartment of theprocess chamber 12, the lift/rotate actuator 54 simultaneously invertsthe wafer 14 and the rotor 20 on which it is held. Particularly, thelift/rotate actuator 54 moves the wafer 14 from a position in the uppercompartment, in which the first side 42 of the wafer 14 faces upwardly,as shown in FIG. 4; to a position in the lower compartment of theprocess chamber 12, in which that first side 42 of the wafer 14 facesdownwardly, as shown in FIG. 6.

In this lower compartment, this downwardly-facing wafer 14 may besubjected to a processing step, as for example through processing with,or by immersion into, a liquid chemical; or processing by treatment witha fluid spray. After the lift/rotate actuator 54 returns the wafer 14 tothe compartment of the process chamber 12, and to a position in whichthe first side 42 again faces upwardly, the processed or treated wafer14 may be rinsed, dried, and then removed from the process chamber 12.

Accordingly, it is apparent that the invention is also an attachment forremovable securement to the deck 19 of a system 10 for processingsemiconductor wafers. This attachment includes the tiltable rim 24,which tilts from the non-inclined position to an inclined position. Asnoted above, this tiltable rim 24 permits the wafers 14 to be loadedinto and unloaded from the system 10, when the rim is in its inclinedposition. The invention also includes a support for securing thetiltable rim 24 to the deck 19. Preferably, this support is a shroud 40.

Recapping the typical process of this invention, using the componentsdescribed above, the process comprises the treatment of semi-conductorwafers 14 within a process chamber 12. The process includes severalsteps. First, tiltable rim 24 at the top of the process chamber 12 istilted from the non-inclined position, as shown in FIGS. 4-7, to theinclined position as shown in FIGS. 2 and 3. The tilting of the rim 24opens the front of the process chamber 12.

Second, a semiconductor wafer 14 is inserted onto a rotor 20 positionedwithin the process chamber 12. As may best be seen in FIGS. 2 and 3, thewafer 14 is preferably inserted onto this rotor 20 by means of a robotarm 16 and a robot end effector 18. Upon such insertion, a first side 42of the wafer 14 is facing upwardly. Upon its initial placement onto therotor 20, the wafer 14 of FIGS. 2 and 3 is positioned in an uppercompartment of the process chamber 12. The tiltable rim 24 is nowreturned to its non-inclined position, closing the process chamber 12.At this point, the wafer may be subjected to an optional processingstep. Next, the wafer 14 and rotor 20 are lowered from this uppercompartment of the process chamber 12 to a lower compartment of theprocess chamber 12. The wafer 14 is shown in the lower compartment ofthe chamber 12 in FIGS. 5 and 6. As the lift/rotate actuator 54 movesthe rotor 20 into the lower compartment of the process chamber 12, itsimultaneously inverts the wafer 14. As a result of this inversion, thefirst side 42 of the wafer 14 faces downwardly.

While the wafer 14 is inverted and disposed within the lowercompartment, it may be subjected to another processing step, such as achemical processing step. After the wafer 14 is processed, thelift/rotate actuator 54 returns the wafer 14 to the upper compartment,and returns the first side 42 of the wafer 14 to its initial position,that is, with its first side 42 facing upwardly. The wafer 14 may thenbe subjected to yet another processing step, including but not limitedto chemical processing, rinsing, and/or drying.

Finally, the tiltable rim 24 is returned to its inclined position. Whenin this inclined position, as best seen in FIG. 3, any fluid that hasbeen collected within the channel 44 is directed to the flexible drainhose fitting 46, and is thereafter discharged from the process chamber12. With the rim 24 in this inclined position, the robot arm 16 removesthe wafer 14 from the process chamber 12.

The use of a shroud and exhaust ports may increase the retention ofchemical vapors within the chamber 12, and may more effectively directdrying air over the wafers 14 used to make microelectronic devices,reducing the likelihood that tiny particles of dust, dirt, metals, andmanufacturing chemicals will remain upon the surface of microelectronicdevices.

What is claimed is:
 1. Processing a workpiece within a process chambercomprising; (a) tilting a rim at the top of the process chamber from anon-inclined position to an inclined position, to open the processchamber; (b) inserting a workpiece onto a holder positioned within theprocess chamber with the holder initially holding the workpiece with afirst side of the workpiece face-up; (c) flipping the workpiece overinto a position with the first side of the workpiece face-down; (d)processing the workpiece within the process chamber via at least oneprocessing step while the workpiece is in the face-down position; and(e) removing the workpiece from the process chamber.
 2. The method ofclaim 1 with the holder comprising a rotor, and further comprisingrotating the workpiece on or in the rotor.
 3. The method of claim 1further comprising pivoting an arm from a first position where the armis above the workpiece to a second position where the arm is off to oneside of the workpiece.
 4. The method of claim 3 further comprisingapplying a processing fluid from the arm onto the workpiece.
 5. Themethod of claim 1 further comprising applying vacuum to a collectionchannel in the rim.
 6. The method of claim 1 further comprising making aconnection between a collection channel in the rim and an exhaust ductwhen the rim is in the non-inclined position, and temporarily breakingconnection between the collection channel and the exhaust duct, when therim is in the inclined position.
 7. The method of claim 1 furthercomprising positioning a shroud around a portion of the process chamberbelow the rim.
 8. The method of claim 1 wherein tilting the rim causes afront side of the rim to move down and a back side of the rim to moveup, further comprising inserting a wafer into a rotor by moving a robotholding a wafer into a position substantially vertically aligned withthe rotor, and with the robot over the front side of the rim. 9.Processing a workpiece within a process chamber, comprising: (a) tiltinga rim at the top of the process chamber on two hinges secured to theprocess chamber, from a non-inclined position to an inclined position,to open the process chamber; (b) inserting a workpiece onto a holderpositioned within the process chamber with the holder initially holdingthe workpiece with a first side of the workpiece face-up; (c) flippingthe workpiece over into a position with the first side of the workpieceface-down; (d) pivoting an arm from a first position where the arm isabove the workpiece to a second position where the arm is off to oneside of the workpiece; (e) processing the workpiece within the processchamber via at least one processing step with the first side of theworkpiece face-down; and (f) removing the workpiece from the processchamber.
 10. The method of claim 1 with the holder comprising a rotor,and further comprising rotating the workpiece on or in the rotor. 11.The method of claim 1 further comprising applying a processing fluidfrom the arm onto the workpiece.
 12. The method of claim 1 furthercomprising applying vacuum to a collection channel in the rim.